Obstetrics Flashcards
Pregnancy has what effect on MAC? when does it return to normal?
decreased by 40%; ~three days after pregnancy
What are the treatments for HoTN during delivery?
phenylephrine/ephedrine, supp O2, L uterine displacement, IVF
Blockade of anterior nerve root fibers causes blockade of what? posterior?
anterior - efferent motor and autonomic outflow; posterior - somatic and visceral sensation
Why do obstetric patients desaturate so quickly?
at term, MV increases by 50% while at the same time FRC decreases by 20%
Why are obstetric patients usually anemic?
at term, blood volume increases by 1-1.5L while plasma volume increases by 45%
What components add to the increased cardiac output of obstetric patients? How much is cardiac output increased?
HR increases 15-20%; SV increases 30%; CO increases 40%
What factors contribute to GERD in obstetric patients?
decreased LE sphincter due to displacement of stomoch by uterus, elevated progesterone, hypersecretion of gastric acid
What is human chorionic somatomamotropin?
a hormone similar to growth hormone; it modifies the metabolic state of the mother to facilitate energy supply to the fetus
What noticeable changes does human chorionic somatomamotropin have on the obstetric patient?
relative insulin resistance (hyperglycemia); increases insulin levels; pancreatic beta cell hyperplasia; gestational diabetes
What causes decreased uterine blood flow?
systemic hypotension, aortocaval compression, uterine vasoconstriction (catecholamines, vasoactive drugs), contractions
What are the two parts of stage 1 labor?
early labor - cervix gradually effaces and dilates up to 3cm; active labor - cervix dilates more rapidly and contractions are longer, stronger and closer together
Where do patients generally feel pain during labor? which dermatomes are these?
stage 1 - (mostly visceral) lower abdomen, lumbosacral area, gluteal region, thighs (T10-L1)
stage 2 - onset of perineal pain (S2-4 [pudential nerve])
What is placenta accreta?
abnormally deep attachment of the placenta to the myometrium
Up to what sensory level does a patient need to be blocked for C-section?
T4
Pain relief during labor needs to be provided at what sensory level during each stage?
stage 1 - T10-L1; stage 2 - T10-S4
Why is it important to preload a patient with IVF? how much should be given?
blood loss, HoTN associated w/ sympathetic blockade; 500-1000cc crystalloid
PDPH is a greater risk in what neuraxial technique? why?
epidural; because a larger needle is used
What are the most important factors for spread/block height in neuraxial anesthesia?
spread (spinal) - baricity (CSF volume important for isobaric); block height (epidural) - injection site
What are the most important factors for duration in neuraxial anesthesia?
spinal - dose; epidural - choice of LA
What are the most important factors for onset in neuraxial anesthesia?
spinal - pKa; epidural - pKa
Which causes more profound HoTN, spinal or epidural?
spinal
How far do you advance the catheter once in the epidural space?
3-5cm
What is the treatment for PDPH?
IV hydration, 500mg caffiene, (epidural blood patch 12-20cc)
What are standard aspiration prophylaxis given and in what dose?
bicitra 30cc, metoclopramide 10mg, famotidine (Pepcid) 20mg
What is dystocia? what are typical causes?
abnormal or difficult labor; abnormal fetopelvic relations, dysfunctional uterine activity
What are reasons for emergent delivery?
amnionitis, fetal distress, impending maternal death, maternal hemorrhage, umbilical cord prolapse, genital herpes with ruptured membranes
What are causes of partum hemorrhage?
placenta previa, abruptio placentae, uterine rupture
What are complications of the fetus/placenta/uterus?
fetus - distress, breech birth; placenta - amnionitis, umbilical cord prolapse, placenta accreta, abruptio placentae, placenta previa; uterus - uterine rupture
What are the diagnoses/treatment for umbilical cord prolapse?
diagnosis - fetal bradycardia; treatment - steep T-berg, push contents back into pelvis then emergency C-section
What is treatment for breech birth presentation?
before delivery - internal/external cephalic version (spinning the baby around while in the womb); vaginal delivery - forceps; mandatory c-section (surgeon preference)
What is the presentation of placenta previa? treatment?
presentation - painless vaginal bleeding; treatment - bed rest before 37 weeks, c-section
What is the most common cause intrapartum death?
abruptio placentae
What are the causes, signs and treatment for abruptio placentae?
causes - bleeding into endometrium; signs - painless vaginal bleeding with uterine contraction and tenderness; treatment - vaginal delivery ok unless fetal destress
What are common causes of uterine rupture?
dehiscence of scar from previous uterine surgery, trauma from forceps, spontaneous from prolonged labor
What are presentations of uterine rupture? treatment?
possible presentations - hemorrhage, fetal distress, loss of uterine tone, HoTN; treatment - IVF and laparotomy (possible hysterectomy)
What constitutes pregnancy-induced HTN?
systolic 140mmHg+ (or rise of 30+), diastolic 90mmHg+ (or rise of 15+)
What constitutes pre-eclampsia? eclampsia?
pre-eclampsia - HTN after 20th wk/resolved after delivery, proteinuria (>500mg/d); eclampsia - pre + tonic-clonic seizures
Treatment for pre-eclampsia?
bed rest, sedation, antihypertensives, magnesium sulphate (to prevent convulsions)
What is HELLP syndrome?
pre-eclampsia associated w/: hemolysis, elevated liver enzymes, low platelet count
What is amniotic fluid embolism?
entry of amniotic fluid into maternal circulation via a break in the uteroplacental membrane
What does amniotic fluid embolism cause? how does it present?
PE, DIC, uterine atony; presents as tachyapnea, cyanosis, shock, bleeding, pulmonary edema, seizures, LV dysfunction
What is treatment for amniotic fluid embolism? why might it be ineffective?
ACLS; aortocaval compression impairs resuscitation with CPR
What drugs are useful in treating post-partum hemorrhage?
pitocin, methergin (for uterine atony),
